Bridge Collapse in Minnesota

The clank of duet I-35W in Minnesota during the rush hour of August 1put tremendous pressure on the reliability and safety of our duads nationwide. Countless investigations and precautionary measures were d angiotensin converting enzyme to pack all couplets pass standard results and render it safe for twain the vehicles and passengers. At the same time it gave dent to our morphologic showingers ability to sum up with a actually sound twist and bridge circuit anatomy. In this research paper we pass on try to dwell into the process involving bridge build, the different radiation diagram load ups, proper bridge rep parentage and the type of bridge design affaird by machinates on the I-35W.After the collapse, we shall in like manner try to decode the expert touch on the real cause and give acceptation to their theory on the failure of the clothes hamper plate. We ordain also discuss the implication of the collapse of the bridge to the technology barter, part icularly if the failure was caused by unsound design theories. And lastly after all is said and through with(p), I depart try to give my assessment on the matter raise on the materials culled from the different websites of the Internet. The blueprint Process The design of a social structure (buildings or bridges) follows a tedious and complex process. twosomes for example needs plain meticulous observation because it carries moving loads and design flaws could only be accurately gauged if the sequence is subjected to a computer generated simulated stress diagrams. In this way structural designers can pinpoint the areas wi burn the structure that is or so likely to suffer fracture in extreme cases of bridge pluck (BridgeArt). In the case of Bridge I-35W in Minneapolis, the designer may pass on been correct in all his assumptions as guided by the Design Manual of the American Institute of stigma Construction (AISC).From the dead load to the perceived moving loads, to the s outright load and impact loads and also the necessary factor of safety were all incorporated in his design observation. Proof of the matter is the said bridge continued to thrive since its erecting in 1967 and only collapsed four decades later. What may select caused the collapse of the bridge? Serious design errors could non be errored because it should have failed at the intrusion when the bridge was first used by the commuting public. Certainly the culprit could be poor maintenance procedures or bridge stamping grounds.The Bridge refurbish Data gathered from MN-DOT reveals that the bridge underwent major deck paving in 1970 and 1990. This twin repairs has already added tremendous dead load to the structure. Prior to the collapse of the bridge another paving was underway and materials were stockpiled on the deck gain the various equipment doing the repair job (Obi-Akpere). The recent resurfacing of the bridge placed an extra deadweight to the structure, roughly or so 300 tons and may have triggered the demise of bridge I-35W (Obi-Akpere).The Bridge Design Design Engineers from the University of Minnesota in its report, found the bridge to be a non-redundant structure meaning that all structural components act together and if one member fails the entire structure would collapse. Besides, the arc structure rests on only four pylons and failure of one in particular during tremors would be catastrophic (Week III). The bridge I-35W is a typical three bridge continuous deck truss with a jargon of steel members and with the thoroughfare on top.To protect the bridge from lateral movement because of extreme temperature changes (expansion and contraction), bridge bearings were used to allow the structure free movement (Week III). The Investigation From the wreckage of the collapsed bridge, investigators found several fractured invalidator plates. Calculations were made on the stress capacity of the gusset plates and were found to be way deficient a nd the loads applied on the bridge were over their design limit. But no design imperfections were notice on the structural members (Samuel).This goes to show that failure of the structure emanates from too thin gusset plates, which could have been a construction error rather than a design flaw. Common sense dictates that a gusset plate should not be lesser in cross sectional area to a particular member served. In this case if proper construction procedure could have been followed, then structural failure should have been evident in the structural members (Roy). Or structure failure could be manifested in the welded joints or on the construction rivets and bolts.But such is not the case, then blame should be shouldered by the contractor for possibly undertaking stringent cost cutting measures or on his failure to notify the design engineer of the little gusset plates. And the MN-DOT field engineers likewise for its failure to spot the defective components installed in the structur e (Gilbert). Also inspections were made by MN-DOT personnel on the bridge, but sad to say that they were unable to spot the defective gusset plates.Any ocular inspection would be useless unless field engineers would dutifully keep back each structural member by using calipers, particularly the oppressiveness of the structural members. All the data are feed to their computer design software and only then can they be certain about their structural assessment (Arti instrument). Implication to Engineering The collapse of bridge I-35W is a slap to the engineering profession, because it ordain tend to show that structural designers failed to post safety nets to our structures not only on bridges but also buildings.It will put into perplexity and scrutiny the methods and theories put forth by icons of the industry. For over 100 years our structural designers have practiced the profession based on the tenets of the formulas perfected by pioneers of the profession and a slipperiness li ke the collapse of the bridge will render all of these to naught. This will have a global effect, because everybody will now put to bear witness the safety of our structures. With a disaster of this magnitude, people will now question the relevance of our structural design principles.Have we really made an accurate engineering theory and formula that could be fundamentally applied to bridge design? Or do we need to further hone our skills in clubhouse to come up with a design principle that will truly address such structural deficiencies? Engineers will now be contrasted because what they have studied and practiced through the centuries will be rendered useless. It will be back to square one since all structures will now be deemed unfit for kind habitation.What will now become of the human population probably live in tents and simple lean-to structures? Development will be in a stand still as everybody will be wary of building structures, much more live in it. But initial findi ng from investigators is a breath of fresh air to structural designers. They only found errors in judgment in the use of materials and components not on the structural design. This will prove beyond doubt that they have practiced sound design principles and that resulting structures are safer than ever. ConclusionIn the ensuing investigation, it is my opinion that what caused the collapse of bridge I-35W is not the design flaws (although evident) but the haphazard repair on the bridge made by personnel of the MN-DOT. Take annotating that resurfacing was made on the bridge for three occasions, one in 1970, 1990, and the one prior to the collapse of the bridge. Each time the bridge was resurfaced, almost 15,000 cuboidal feet of material was poured over it. This is only for the longest span of 458 feet and a breadth of 113 feet or roughly 8 road lanes, the one span directly over the river.This alone constitutes over 2,500 tons added to the original design load, and since this is do ne three times, the spare deadweight is tremendous. At the time of the incident equipment and materials were stockpiled making the structure grossly overloaded, no wonder the bridge collapsed (Week III). By the way repairs have been made on the bridge, it was actually an accident waiting to happen. It was never the fault of the structural designer, not even the contractor for he knew his responsibilities.But had they followed the steel design manual on gusset plate design, the structure could have survived the additional deadweight imposed on it. References American Institute of Steel Construction, Inc. 1967. Manual of Steel Construction. sixth ed. American Institute of Steel Construction United States. Artifactor. I-35W Bridge over Mississippi River collapsed Science Buzz. 2 August 2007. Science Museum of Minnesota. 4 February 2008. .BridgeArt. 2007. Long Tail Group. 4 February 2008. http//www. bridgeart. net/software_database/. Gilbert, Steve. Design faulting caused MN bridge collapse. Sweetness and Light. 15 January 2008. 4 February 2008. http//sweetness-light. com/archive/design-flaw-caused-mn-bridge-collapse. Obi-Akpere. The Critical Factor Why Minneapolis Bridge Collapsed. NowPublic. 16 January 2008. 3 February 2008. http//www. nowpublic. com/environment/critical-factor-why-minneapolis-bridge-collapsed. Roy, Jennifer.Design Flaw Identified in Minnesota Bridge Collapse. Design News. 15 January 2008. 4 February 2008. http//www. designnews. com/article/CA6522883. html. Samuel, Peter. MN/I-35W bridge collapsed because several gusset plates were grossly undersized engineering error the cause. TollRoadsnews. 15 January 2008. 3 February 2008. http//www. tollroadsnews. com/node/3346. Weeks III, John A. grey-haired I-35W Bridge. John Weeks Homepage. 2005. 3 February 2008. http//www. visi. com/jweeks/bridges/pages/ms16. html.